Science and technology

The science of music

Same old song

THE kids these days play their music too loud and it all sounds the same. Old fogies familiar with such sentiments will be happy to hear that maths bears them out. An analysis published in Scientific Reports by Joan Serrà of the Artificial Intelligence Research Institute in Barcelona and his colleagues has found that music has indeed become both more homogeneous and louder over the decades.

Dr Serrà began with the basic premise that music, like language, can evolve over time, often pulled in different directions by opposing forces. Popular music especially has always prized a degree of conformity—witness the enduring popularity of cover songs and remixes—while at the same time being obsessed with the new. To untangle these factors, Dr Serrà's team sifted through the Million Song Dataset, run jointly by Columbia University, in New York, and the Echo Nest, an American company, which contains beat-by-beat data on a million Western songs from a variety of popular genres. The researchers focussed on the primary musical qualities of pitch, timbre and loudness, which were available for nearly 0.5m songs released from 1955 to 2010.

They found that music today relies on the same chords as music from the 1950s. Nearly all melodies are composed of ten most popular chords. They follow a similar pattern to written texts, where the most common word occurs roughly twice as often as the second most common, three times as often as the third most common, and so on, a linguistic regularity known as Zipf's law. What has changed is how the chords are spliced into melodies. In the 1950s many of the less common chords would chime close to one another in the melodic progression. More recently, they have tended to be separated by the more pedestrian chords, leading to a loss of some of the more unusual transitions. Timbre, lent by instrument types and recording techniques, similarly shows signs of narrowing, after peaking in the mid-60s, a phenomenon Dr Serrà attributes to experimentation with electric-guitar sounds by Jimi Hendrix and the like.

What music lost in variety, it has gained in volume. Songs today are on average 9 decibels louder than half a century ago, confirming what industry types have long suspected: that record labels engage in a "loudness race" in order to catch radio listeners’ attention. Since digital audio formats max out at a certain decibel level, as the average loudness inches towards that ceiling, songs will lose dynamic range, becoming ever more uniform.

This homogeneity is not just jarring to melomaniacs. It might confuse the popular algorithms for identifying and recommending tracks, like those used by Spotify and other music services. Many of these rely on timbre measurements to sort songs into genres, for instance. Some musicians are bound to respond by confounding expectations with new sounds. Whether audiences wish to be confounded remains moot.

I am an audio electronics engineer and I deal with dBSPL, dBFS, dBrA, dBV, and many other audio-related decibel units on a daily basis, so I have to jump in here to correct you both. I'm not trying to one-up you or insult you or anything - I just want to correct the inaccuracies here.

Kent Williams, you're correct when you say that the decibel unit is meaningless when used without a reference. However, dB RMS is equally as meaningless. RMS is simply a way to calculate the average level of a signal over time (which contrasts with a peak measurement). It does not provide a reference.

In order to reference the measurement, you need to use a reference measurement lik dBV RMS, dBSPL RMS, dBOV RMS, or dBFS RMS.

The author is talking about recording media, so dBSPL, which can only be used in an acoustic system, has no meaning here.

Scotland777, as I mentioned above, dBSPL (sound pressure level) actually has no meaning with regard to audio recordings. dBSPL is a measurement of sound pressure in an actual acoustic listening environment, which means it relies on the speakers, the distance from the listener, the power of the signal through the speaker, and the air through which the acoustic signal propagates. It has no relation to the recording medium.

The measurement referred to in the article is actually dBFS (decibels full scale) in the case of CDs. 0 dBFS (peak) refers to the absolute maximum level that can be represented in the digital recording medium. In analog recording media, the maximum level is 0 dBOV (peak), which refers to the maximum analog level that can be reached without clipping in the electrical domain.

In both cases (analog and digital recording media), what defines "loudness" is the ratio between the average (RMS) level and the peak level of the recorded signal. It's true that this ratio has increased for modern recordings, which conversely decreases the dynamic range of the recording. Metallica's "Death Magnetic" album has one of the lowest dynamic ranges of all time. This is what is commonly referred to as the "loudness war."

I guess you can't blame the author (or the public) for not having a solid understanding of a pretty complex technical concept.

In any case, the author said that the recordings are 9 dB louder. This refers to the crest factor (peak/RMS), which is a power ratio, and our ears distinguish loudness as a power ratio, not a linear ratio. 9 dB equates to a power ratio of 7.9. Basically, it means that music has gotten 7.9 times "louder" in the past 50 years. Another way to think of it is that the dynamic range has decreased by a whopping 88%.

I think there's some backward science going on here. Probably conducted by these old fogies mentioned in the opening sentences.

While it *might* be true that top 40 music is more homogenous than ever before, and probably true that dynamic range is decreasing, there is no way it's true that music as a whole is more homogenous.

The advent of computers has undoubtedly increased the variety of music we see. First, it has allowed small artists and genres to reach a wider audience through the internet. Some of these are creative types that are doing truly new things with sound.

Second, and more importantly, are the computer generated sounds that we hear today. Computers allow so much more variety in frequency, beat, dynamic range, harmonization, sampling, etc. Name a musical trait and the computer can do more than the human. Of course they can't sing (yet) but sampling a human's voice into an otherwise electronic song gives the full advantage of the human, but with more versatility.

Lesson to be learned: source data determines the result. Don't judge the whole world of music on a database of music which most likely is not representative.

No no, they're talking about the level in which it was recorded to tape (er, to hard drive). And compression plays a large role in this. Think of it like mountains and valleys ... the mountains in most music are the same height, but the valleys, even 10 years ago, were lower ... so there was more dynamic range between, say, a verse and a chorus in the same song. Today, they're slamming everything so hard that they have to compress the tracks harder, thus the valleys end up being just as tall as the mountains. What does this mean? There is less and less range in any given song today ... the verses, choruses, the singing ... it's all at a continuous volume. THEN, when it's played on the radio, it gets compressed even more. You should read up on the "volume wars" some time, kind of interesting. Anyway, sorry for so many words, but the author of this article didn't go into the technical aspect as much as they should have to fully explain what it means. Hope I did a reasonable job with the whole mountains and valley thing.

Regarding the comment: "music today relies on the same chords as music from the 1950s", I believe that what the author meant was chord progression and not chords. Of course we use the same chords they used in the '50s (even the 1750's). The bad thing is that we use the same chord progression as well... This is what makes music sound the same.

Another thing that we have to mention is that the facts of the article cover pop music (or rock 'n' roll if you like). It does not apply to symphonic music or jazz...

Well, as someone who has studied music and plays piano and guitar as a hobby, I think that the idea that the creative music population was somehow smaller in the past is a bit of a myth. I would actually posit that, on a per capita basis, the ratio of music creators and participants was actually higher in the past.

Remember that our ancestors had no TV, no movies, no electronic destractions. If you wanted to entertain yourself, you had to do it yourself. Today, most people are involved in music solely as passive listeners. Two hundred years ago, if you wanted to listen to music, you generally had to sit down at a piano or other instrument and play it yourself. Folk music was widespread, church music was widespread, public singing was commonplace, and by the late-18th century public entertainment like opera was rampant among nearly all social classes. People churned out loads of music -- it is just that today we don't listen to 99% of it because 99% of it is pretty ordinary and forgettable. Also, a lot of it was simply never preserved (for example, it is pretty clear that the Ancient Greeks were awash in music in a slew of public activities, but sadly only a few fragments have survived to be passed on to us today. It was also harder to disseminate music in the past, since all of it had to be scribed by hand for centuries. It is only in the modern age that we have become globally aware of the musical traditions of other countries and cultures, and have the technology to spread it far and wide (but that is not the same thing as saying there is "more" music now than in the past, it is merely that we are more aware of what is out there).

Don't assume that just because all sorts of music can appear magically at the mere touch of a button, that somehow we are more prolific today than we were in the past. Any student of music history can tell you otherwise.

Huh... a baby making gurgling sounds? This is innovative? I think you need to uncork Pink Floyd's "Dark Side of the Moon" and listen from beginning to end, and you will find a remarkable use of spoken voices and sounds of daily life interwoven into the songs as well as in the transitions between songs. Great stuff.

Simon and Garfunkle also had a great album "Bookends", which had a track "Voices of Old People". Side one of the album is about the phases of aging, and the track fits in nicely with the theme (although side two has the more memorable songs on it).

I love it when folks talk about "innovation" before realizing that some artists did the exact same thing 30 or 40 years earlier.

By comparing the whole database, I think we're missing an important point. A listener of the 50s--whether the 1750s or the 1950s--had access to only a very small percentage of the music produced.

With the digital world, access to music, and types of music, is much greater. As a college student in the 1970s, I struggled to afford the $6-$8 for a single new vinyl album. And these albums were mostly rock (I was fortunate to have room-mates who purchased jazz and classical).

Today, I have most of these vinyl albums in digital. In addition, I have hundreds of other "albums" in digital....in genres that wouldn't have been commonly available or noted in the limited analog age.

Painted with a broad brush the 1950s--or the hits we fondly latch onto--are interesting. Listen to all of the songs on a regular basis, and they also start to sound the same.

And lets not forget to discuss the effect that Apple and Steve Jobs have had in promoting horrible fidelity and music reproduction by choosing and pushing the horrid mp3 format. For this alone, Mr. Jobs can be referred to as the Ray Kroc of the digital age....

If you think that today's music hasn't narrowed in timbre and its attendant recording techniques have been essentially dulled over the last few decades, you are severely out of touch with current popular music and its history. The fact is, whether or not the science is spot-on, this article reflects the current reality of pop music.

All hail Tom Waits. He will continue to be the outlier in the trend until his demise. We could use a heavy dose of 70's British Prog Rock to flatten the progression or someone could reanimate Thelonios Monk. Better yet create some obscure super group with Zombie Monk on piano, Tom on vocals, Robert Fripp on guitar and a heavy dose of Bill Bruford on drums. Modern listeners may not even recognize it as music.

"Starless and Bible Black" is one of my closet favorites, but I guess the average listener might not fully appreciate Fripp's viruosity (which is why most of my friends in college would only spin that record if they were high on something). It is a shame, really -- it is extraordinarily complex music, given its genre. It is just not a toe-tapper that the pop masses would appreciate.

Fascinating stuff. Count me in with the fogeys - today's music is for the most part utterly banal. Computers homogenize more than innovate. Nobody today is doing anything close to Hendrix, much less Bach.